PARIS, Dec. 7 (Xinhua) -- The latest educational assessment report released by the Organization for Economic Cooperation and Development (OECD) on Tuesday showed that girls outdo boys in reading literacy in all economies surveyed by the organization in 2009.

Based on two-hour tests of a half million students in more than 70 economies, the 2009 report of the Program for International Student Assessment (PISA) found that girls read better than boys in every participating country by an average of 39 points in the scale.

The gender gap in reading is equivalent to one year of schooling, which has not improved in any country since 2000, the OECD said, adding the gap widened in France, Israel, South Korea, Portugal and Sweden mainly resulted from a decline of boy's enjoyment of reading and their engagement with leisure reading.

Regarding to joyful reading for both genders, less students said they read for pleasure as the percentage dropped from 69 percent in 2000 to 64 percent in 2009, according to the PISA report.

The elaborately designed tests also covering reading literacy, mathematics and science, nevertheless, found that boys outperform girls in mathematics by 12 score points while gender differences in science performance are very small.

"The ranks of top-performing students are filled nearly equally with girls and boys" in all three subjects, the report added, a fact defying the conventional view spreading many ages that girls are less likely to make achievements in science.